Circinella pseudohomothallica (Mucorales, Mucoromycota), a new species from soil of a cave in the Brazilian dry forest (Caatinga)

During a survey of fungi in the Furna Nova cave of the Brazilian dry forest (Caatinga), two specimens of <i>Circinella</i> (URM 9081 and URM 9082) were isolated. Based on morphological and molecular data (ITS and LSU rDNA regions), a new species that is closely related to <i>Circinella homothallica</i> is delimited. The isolates form light grey to dark brown colonies and reverse yellowish. Dimorphic, short and tall sporangiophores are formed. Short sporangiophores are circinate, unbranched or sympodially branched, while the tall ones are erect, unbranched or simply branched, with some showing a swelling below apophyses. Sporangia of tall sporangiophores are deliquescent-walled, while the ones of short sporangiophores are persistent-walled. Sporangiospores are hyaline and elliptical, some with rounded ends. Zygosporangia are homothallic, yellow to brown, ornamented-walled, and suspensors are opposed and unequal in shape and size. This study contributes to the knowledge of <i>Mucoromycota</i> species in Brazilian caves.